Typically, electronic devices refer to devices that perform a specific function according to installed programs, such as electronic organizers, portable multimedia players, mobile communication terminals, tablet PCs, video/audio devices, desktop/laptop computers, or car navigation units, as well as home appliances. For example, such electronic devices may output stored information in sounds or images. With the high integration of the electronic device and the propagation of high-speed and high-capacity wireless communication, in recent years, an entertainment function (such as games), a multimedia function (such as the reproduction of music/videos), a communication and security function for the mobile banking, or a function of a scheduler or an electronic wallet have been integrated into a single electronic device.
In addition, various types of wearable electronic devices have been introduced, which can be worn on the body to then be used, such as glasses or watches.
These electronic devices may be provided with rotary input device in various forms. The rotary input device may be provided in order to: turn on the electronic device in the power-off mode; execute the electronic device in the sleep mode in which the power is supplied; or execute functions of the electronic device to allow the electronic device to receive inputs in the driving mode.
The rotary input device may include a physical rotary input device that implements the input, for example, by pressing button keys, and a touch rotary input device that implements the input through a touch or the proximity. In addition, since the user cannot recognize the input by the sense of touch in the case of making an input in the touch rotary input device, a haptic device may be further provided in order to provide the user with a similar sense as the conventional physical rotary input device with respect to the user's touch.
Furthermore, the wearable device, such as a smart watch, has a limit in mounting the rotary input device due to its miniaturization. That is, a space for mounting the physical rotary input device is too small, and even if the rotary input device is mounted therein, the wearable device has a limit in implementing various types of inputs because it is extremely small.
In addition, the wearable device, such as a smart watch, may include a bezel portion that rotates in the circumferential portion of a display (hereinafter, referred to as a “bezel area”) that is provided in a body of the smart watch, and a sensor unit that recognizes the rotation of the bezel portion so that the sensor unit recognizes the rotation of the bezel portion in order to thereby implement the input.
However, when the input is implemented through the rotation recognition by the sensor as described above, a separate mechanical structure is utilized: to detect the rotation of the bezel portion, separately from the sensor unit; or to provide tactile feedback in order for the sensor unit to sense the input implemented by the rotation of the bezel portion.
In addition, an additional circuit or mechanical circuit structure is utilized in order for the sensor unit to recognize the rotation of the bezel portion.
In addition, when the sensor unit is a magnetic sensor, a metal material, which may cause the generation of a signal in the magnetic sensor, cannot be used for the bezel portion or the electronic device in consideration of the characteristics of the magnetic sensor.
Furthermore, when the sensor unit is an optical sensor, the reflectivity of a light incident on the optical sensor is utilized to be altered in order to recognize the rotation of the bezel portion. To this end, a separate plate or additional operation may be added for making the reflectivity of a light different in the bezel portion.